CN110741169A - Oil pressure system - Google Patents
Oil pressure system Download PDFInfo
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- CN110741169A CN110741169A CN201880019230.9A CN201880019230A CN110741169A CN 110741169 A CN110741169 A CN 110741169A CN 201880019230 A CN201880019230 A CN 201880019230A CN 110741169 A CN110741169 A CN 110741169A
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- Prior art keywords
- electromagnetic proportional
- proportional valve
- valve
- secondary pressure
- pressure
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- E—FIXED CONSTRUCTIONS
- E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
- E02F—DREDGING; SOIL-SHIFTING
- E02F9/00—Component parts of dredgers or soil-shifting machines, not restricted to one of the kinds covered by groups E02F3/00 - E02F7/00
- E02F9/20—Drives; Control devices
- E02F9/22—Hydraulic or pneumatic drives
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
- F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
- F15B11/00—Servomotor systems without provision for follow-up action; Circuits therefor
- F15B11/02—Systems essentially incorporating special features for controlling the speed or actuating force of an output member
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
- F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
- F15B11/00—Servomotor systems without provision for follow-up action; Circuits therefor
- F15B11/02—Systems essentially incorporating special features for controlling the speed or actuating force of an output member
- F15B11/04—Systems essentially incorporating special features for controlling the speed or actuating force of an output member for controlling the speed
- F15B11/042—Systems essentially incorporating special features for controlling the speed or actuating force of an output member for controlling the speed by means in the feed line, i.e. "meter in"
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
- F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
- F15B11/00—Servomotor systems without provision for follow-up action; Circuits therefor
- F15B11/16—Servomotor systems without provision for follow-up action; Circuits therefor with two or more servomotors
- F15B11/17—Servomotor systems without provision for follow-up action; Circuits therefor with two or more servomotors using two or more pumps
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
- F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
- F15B20/00—Safety arrangements for fluid actuator systems; Applications of safety devices in fluid actuator systems; Emergency measures for fluid actuator systems
Abstract
The hydraulic system includes a and a second electromagnetic proportional valve that output higher secondary pressures as operation signals output from and a second operation device become larger, a third electromagnetic proportional valve that output higher secondary pressures as an operation amount of a operation device becomes larger when a electromagnetic proportional valve does not function normally, and output higher secondary pressures as an operation amount of a second operation device becomes larger when a second electromagnetic proportional valve does not function normally, a high-pressure selector valve that selects a side higher between the secondary pressure output from a -th electromagnetic proportional valve and the secondary pressure output from the third electromagnetic proportional valve and that leads the secondary pressure to an -th regulator, and a second high-pressure selector valve that selects a side higher between the secondary pressure output from the second electromagnetic proportional valve and the secondary pressure output from the third electromagnetic proportional valve and that leads the secondary pressure to a second regulator for the pump.
Description
Technical Field
The present invention relates to an electric Positive Control (Positive Control) hydraulic system.
Background
Conventionally, an electric positive control type hydraulic system is used in construction machines, industrial machines, and the like. For example, patent document 1 discloses a hydraulic system 100 for a construction machine as shown in fig. 3.
In the hydraulic system 100, the hydraulic oil is supplied from the variable displacement pump 110 to each hydraulic actuator 130 via the control valve 120. The control valve 120 increases the opening area of a passage through which the hydraulic oil is supplied to the hydraulic actuator 130 as the amount of operation of the corresponding operation unit (operation lever in fig. 4) of the operation device 140 increases.
The tilt angle of the pump 110 is adjusted by the adjuster 111. The regulator 111 is connected to an electromagnetic proportional valve 112. The electromagnetic proportional valve 112 outputs a higher secondary pressure as the operation amount of the operation portion of the operation device 140 is larger. Accordingly, the discharge flow rate of the pump 110 increases as the operation amount of the operation unit of the operation device 140 increases.
Prior art documents:
patent document 1, Japanese patent application laid-open No. 10-61604.
Disclosure of Invention
The problems to be solved by the invention are as follows:
however, in the hydraulic system 100 shown in fig. 3, when the proportional solenoid valve 112 fails to function normally due to a failure or the like, the secondary pressure of the proportional solenoid valve 112 may become zero. In this case, even when the operation portion of the operation device 140 is operated, the discharge flow rate of the pump 110 is maintained at the minimum discharge flow rate, and the hydraulic actuator 130 cannot be operated at a sufficient speed. To eliminate this problem, it is conceivable, for example, to provide a redundant electromagnetic proportional valve.
The hydraulic system may include a plurality of pumps for supplying the hydraulic actuator with the hydraulic oil. In such a hydraulic system, for example, when a backup electromagnetic proportional valve is provided for each pump, the cost increases.
Therefore, an object of the present invention is to provide a hydraulic system including the th pump and the second pump of the variable displacement type, which can cope with a failure of the electromagnetic proportional valve and the like with an inexpensive configuration.
Means for solving the problems:
to solve the above problems, a 4624 type of hydraulic system according to the present invention provides type of hydraulic system including and a second operation device outputting operation signals according to an operation amount of an operation portion, a variable displacement type pump supplying working oil to a second hydraulic actuator via a control valve, a second 5 regulator increasing a tilt angle of the pump as a control pressure increases, a variable displacement type second pump supplying working oil to the second hydraulic actuator via a second control valve, a second regulator increasing a tilt angle of the second pump as a control pressure increases, a electromagnetic proportional valve outputting a higher secondary pressure as an operation signal output from the operation device is larger, a second electromagnetic proportional valve outputting a higher secondary pressure as an operation signal output from the second operation device is larger, a third electromagnetic proportional valve outputting a higher secondary pressure as an operation signal output from the second electromagnetic proportional valve is larger when the second electromagnetic proportional valve does not function, and a third electromagnetic proportional valve selecting switch outputting a higher secondary pressure selected from among the second pilot pressure and the second pilot pressure 8934 as a pilot pressure, wherein the second pilot pressure is higher when the second electromagnetic proportional valve is output from the second electromagnetic proportional valve is selected 3637 and the second electromagnetic proportional valve is output as a pilot pressure higher.
According to the above configuration, when the th electromagnetic proportional valve is normal, the th regulator is supplied with the secondary pressure of the 0 th electromagnetic proportional valve, and the tilt angle (discharge flow rate) of the th pump can be controlled by the th electromagnetic proportional valve, and , when the th electromagnetic proportional valve does not function normally and the secondary pressure thereof becomes zero, the th regulator is supplied with the secondary pressure of the third electromagnetic proportional valve in accordance with the operation signal output from the th operation device, and the tilt angle of the th pump increases as the operation signal increases, and as a result, the th hydraulic actuator can be operated at a sufficient speed.
Similarly, when the second electromagnetic proportional valve is normal, the secondary pressure of the second electromagnetic proportional valve is introduced into the second regulator, and the tilt angle (discharge flow rate) of the second pump can be controlled by the second electromagnetic proportional valve, and when the secondary pressure of the second electromagnetic proportional valve becomes zero because the second electromagnetic proportional valve does not function normally, the secondary pressure of the third electromagnetic proportional valve is introduced into the second regulator in accordance with the operation signal output from the second operation device, and the tilt angle of the second pump increases as the operation signal increases, and as a result, the second hydraulic actuator can be operated at a sufficient speed.
In addition, the third electromagnetic proportional valve is a backup for both the th electromagnetic proportional valve and the second electromagnetic proportional valve, so that a trouble of the th electromagnetic proportional valve and the second electromagnetic proportional valve can be dealt with by an inexpensive configuration.
For example, the hydraulic system may further include a control device that supplies a drive current to the th, second, and third electromagnetic proportional valves, wherein the control device changes the drive current to be supplied to the third electromagnetic proportional valve in accordance with an operation signal output from the th operation device when it is determined that the th electromagnetic proportional valve does not function normally based on monitoring of the drive current to be supplied to the th electromagnetic proportional valve, changes the drive current to be supplied to the third electromagnetic proportional valve in accordance with an operation signal output from the second operation device when it is determined that the second electromagnetic proportional valve does not function normally based on monitoring of the drive current to be supplied to the second electromagnetic proportional valve, and sets the drive current to be supplied to the third electromagnetic proportional valve to zero when it is determined that both the th and second electromagnetic proportional valves function normally.
In addition, the invention provides a hydraulic system comprising a 0 operation device and a second operation device which output an operation signal corresponding to an operation amount of an operation portion, a 3 rd pump of a variable displacement type which supplies a working oil to a 2 nd hydraulic actuator via a 1 st control valve, a 5 th regulator which increases a tilt angle of the 4 th pump as a control pressure increases, a second pump of a variable displacement type which supplies a working oil to a second hydraulic actuator via a second control valve, a second regulator which increases a tilt angle of the second pump as a control pressure increases, a second proportional valve which is connected to the 7 th regulator via a 6 th secondary pressure line and which outputs a higher secondary pressure as the control pressure to the 9 th regulator as an operation signal output from the 8 th operation device is larger as the control pressure is output from the 9 th regulator, a second secondary pressure line which is connected to the second regulator as the second relay pressure signal output from the second operation device is larger as the second relay pressure control pressure is higher as the second relay pressure control pressure is output from the second relay pressure control device and the second relay pressure control pressure is higher as the second relay pressure is output from the second relay pressure control device to the upstream side of the second relay pressure control device, the second relay pressure control device is output from the second relay pressure control device, the upstream side of the second relay pressure control device, the second relay pressure control device is set when the second relay pressure control pressure is higher as the second relay pressure control pressure is output from the second relay pressure control device, the second relay pressure control device is output from the upstream side of the second relay pressure control device, the second relay pressure control device is higher as the second relay pressure control device is output from the second relay pressure control device, the upstream side of the upstream relay pressure control device, the second relay pressure control device is set from the second relay pressure control device, the upstream side of the second relay pressure control device is set from the second relay pressure control device, the upstream side of the second relay pressure control device, the second relay pressure control device is set to the upstream side of the upstream relay pressure control device, the second relay pressure control device is set to the second relay pressure control device, the upstream relay pressure control device is set point of the second relay pressure control device, the upstream relay pressure control device is set when the second relay pressure control device is set from the second relay pressure control device, the second relay pressure control device is set point of the second relay pressure control device is set to the second relay pressure control device, the second relay pressure control device is set when the second relay pressure control device, the second relay pressure control device is set to the second relay pressure control device, the second relay pressure control device is set to the second relay pressure control device is set when the second relay pressure control device is set to the second relay pressure control device, the second relay pressure control device is set to the second relay pressure control.
According to the above configuration, when the th electromagnetic proportional valve is normal, the th switching valve is located at the operating position, and the secondary pressure of the 1 th electromagnetic proportional valve is introduced into the 0 th regulator, so that the tilt angle (discharge flow rate) of the th pump can be controlled by the 2 th electromagnetic proportional valve, and on the other hand, , when the th electromagnetic proportional valve does not function normally and the secondary pressure thereof becomes zero, the th switching valve is switched to the neutral position, and the secondary pressure of the second electromagnetic proportional valve corresponding to the operation signal output from the th operation device is introduced into the th regulator, so that the tilt angle of the th pump increases as the operation signal increases, and as a result, the th hydraulic actuator can be operated at a sufficient speed.
Similarly, when the second electromagnetic proportional valve is normal, the second switching valve is located at the operating position, and the secondary pressure of the second electromagnetic proportional valve is introduced into the second regulator, so that the tilt angle (discharge flow rate) of the second pump can be controlled by the second electromagnetic proportional valve, and in addition , when the second electromagnetic proportional valve does not function normally and the secondary pressure thereof becomes zero, the second switching valve is switched to the neutral position, and the secondary pressure of the electromagnetic proportional valve corresponding to the operation signal output from the second operation device is introduced into the second regulator, so that the tilt angle of the second pump increases as the operation signal increases, and as a result, the second hydraulic actuator can be operated at a sufficient speed.
Further, since only the switching valve provided in the th secondary pressure line and the second secondary pressure line is additionally required as compared with the conventional art, it is possible to cope with a failure of the th electromagnetic proportional valve and the second electromagnetic proportional valve with an inexpensive configuration.
The invention has the following effects:
according to the present invention, it is possible to cope with a failure of the electromagnetic proportional valve and the like with an inexpensive configuration in the hydraulic system including the th pump and the second pump of the variable displacement type.
Drawings
Fig. 1 is a schematic configuration diagram of an oil pressure system according to an th embodiment of the present invention;
fig. 2 is a schematic configuration diagram of an oil pressure system according to a second embodiment of the invention;
fig. 3 is a schematic configuration diagram of a hydraulic system of a conventional construction machine.
Detailed Description
(embodiment )
Fig. 1 shows a hydraulic system 1A according to an embodiment of the present invention, the hydraulic system 1A is mounted on a construction machine such as a hydraulic excavator or a hydraulic crane, a civil engineering machine, an agricultural machine, or an industrial machine.
Specifically, the hydraulic system 1A includes -th and second hydraulic actuators 26 and 27, a -th main pump 21 that supplies hydraulic oil to the -th hydraulic actuator 26 via a -th control valve 3A, and a second main pump 23 that supplies hydraulic oil to the second hydraulic actuator 27 via a second control valve 3B.
In the illustrated example, the -th hydraulic actuator 26 and the -th control valve 3A are in combination (set), but a plurality of -th hydraulic actuators 26 and -th control valves 3A may be provided, and similarly, a plurality of second hydraulic actuators 27 and second control valves 3B may be provided in combination of in combination, but a plurality of second hydraulic actuators 27 and second control valves 3B may be provided.
The th and second main pumps 21 and 23 are variable displacement pumps whose tilt angles are variable, respectively, the th and second main pumps 21 and 23 may be swash plate pumps or swash shaft pumps, respectively, the tilt angle of the th main pump 21 is adjusted by the th regulator 22, and the tilt angle of the second main pump 23 is adjusted by the second regulator 24.
The main pump 21 is connected to the control valve 3A via the supply line 11. the discharge pressure of the main pump 21 is maintained at or below the discharge pressure by an unillustrated relief valve. similarly, the second main pump 23 is connected to the second control valve 3B via the supply line 12. the discharge pressure of the second main pump 23 is maintained at or below the discharge pressure by an unillustrated relief valve.
In the present embodiment, the -th hydraulic actuator 26 is a reciprocating cylinder, and the -th control valve 3A is connected to the -th hydraulic actuator 26 through with respect to the supply and discharge line 31, however, the -th hydraulic actuator 26 may be a single-acting cylinder, the -th control valve 3A may be connected to the -th hydraulic actuator 26 through supply and discharge lines 31, or the -th hydraulic actuator 26 may be a hydraulic motor.
Similarly, in the present embodiment, the second hydraulic actuator 27 is a double acting cylinder, and the second control valve 3B is connected to the supply/discharge line 32 and the second hydraulic actuator 27 through , but the second hydraulic actuator 27 may be a single acting cylinder, and the second control valve 3B may be connected to the second hydraulic actuator 27 through supply/discharge lines 32, or the second hydraulic actuator 27 may be a hydraulic motor.
The th control valve 3A is switched from the neutral position to the th position (the position where the th hydraulic actuator 26 is operated in the direction) or the second position (the position where the th hydraulic actuator 26 is operated in the reverse direction) by operating the th operating device 4A in the present embodiment, the th control valve 3A is of a hydraulic pilot type and has pairs of pilot ports, but the th control valve 3A may be of a solenoid pilot type.
Similarly, the second control valve 3B is switched from the neutral position to the th position (the position where the second hydraulic actuator 27 is operated in the direction) or the second position (the position where the second hydraulic actuator 27 is operated in the reverse direction) by the operation of the second operating device 4B, and in the present embodiment, the second control valve 3B is of a hydraulic pilot type and has pairs of pilot ports, but the second control valve 3B may be of a solenoid pilot type.
The th operation device 4A has an operation unit 41 that outputs an operation signal according to the amount of operation on the operation unit 41, that is, the operation signal output from the th operation device 4A increases as the amount of operation increases, the operation unit 41 is, for example, an operation lever, but may be a foot pedal or the like.
In the present embodiment, the -th operation device 4A is a pilot operation valve that outputs a pilot pressure as an operation signal, and therefore the -th operation device 4A is connected to the pilot port of the -th control valve 3A through , and the -th control valve 3A increases the opening area of a passage that supplies hydraulic oil to the -th hydraulic actuator 26 as the pilot pressure (operation signal) output from the -th operation device 4A increases, but the -th operation device 4A may be an electric control lever (joystick) that outputs an electric signal as an operation signal, and in this case, each pilot port of the -th control valve 3A is connected to a secondary pressure port of the electromagnetic proportional valve.
Similarly, the second operation device 4B includes an operation unit 43, and outputs an operation signal according to an operation amount to the operation unit 43. That is, the operation signal output from the second operation device 4B becomes larger as the operation amount becomes larger. The operation unit 43 is, for example, an operation lever, but may be a foot pedal or the like.
In the present embodiment, the second operation device 4B is a pilot operation valve that outputs a pilot pressure as an operation signal, and therefore, the second operation device 4B is connected to the pilot port of the second control valve 3B through to the pilot conduit 44, and the second control valve 3B increases the opening area of the passage through which the hydraulic oil is supplied to the second hydraulic actuator 27 as the pilot pressure (operation signal) output from the second operation device 4B increases.
The -th regulator 22 increases the tilt angle of the -th main pump 21 as the control pressure directed to the -th regulator 22 increases, the -th regulator 22 is connected to the secondary pressure port of the -th electromagnetic proportional valve 51 via the -th high-pressure selector valve 61, the -th primary pressure port of the -th electromagnetic proportional valve 51 is connected to the sub-pump 25 via the -th primary pressure line 13, and the discharge pressure of the sub-pump 25 is maintained at the set pressure by an unillustrated relief valve.
Similarly, the second regulator 24 increases the tilt angle of the second main pump 23 as the control pressure directed to the second regulator 24 increases, the second regulator 24 is connected to the secondary pressure port of the second electromagnetic proportional valve 52 via the second high-pressure selector valve 65, the secondary pressure port of the second electromagnetic proportional valve 52 is connected to the secondary pump 25 through the secondary pressure line 14.
The -th high pressure selector valve 61 has two input ports and output ports, the output ports being connected to the 0-th regulator 22 through an output line 62, and the 1-th input port being connected to the secondary pressure port of the 2-th electromagnetic proportional valve 51 through an input line 63. furthermore, the other input ports of the -th high pressure selector valve 61 are connected to the secondary pressure port of the third electromagnetic proportional valve 53 through an input line 64. that is, the -th high pressure selector valve 61 selects the higher side of the secondary pressure output from the -th electromagnetic proportional valve 51 and the secondary pressure output from the third electromagnetic proportional valve 53 as the above-mentioned control pressure and directs it to the -th regulator 22. the -th pressure port of the third electromagnetic proportional valve 53 is connected to the sub-pump 25 through the -second pressure line 15.
Similarly, the second high pressure selector valve 65 has two input ports and output ports, the output ports being connected to the second regulator 24 through an output line 66, and input ports being connected to the secondary pressure port of the second electromagnetic proportional valve 52 through an input line 67. furthermore, another input ports of the second high pressure selector valve 65 are connected to the secondary pressure port of the third electromagnetic proportional valve 53 through an input line 68. that is, the second high pressure selector valve 65 selects the higher side of the secondary pressure output from the second electromagnetic proportional valve 52 and the secondary pressure output from the third electromagnetic proportional valve 53 as the above-described control pressure and directs it to the second regulator 24.
The th, second, and third electromagnetic proportional valves 51, 52, and 53 are of a proportional type that outputs a higher secondary pressure as the drive current increases, respectively, the th, second, and third electromagnetic proportional valves 51, 52, and 53 are controlled by the control device 7, and in more detail, the control device 7 supplies the drive currents based on the respective command currents to the th, second, and third electromagnetic proportional valves 51, 52, and 53, respectively, although only a portion of the signal lines is drawn in fig. 1 to simplify the drawing.
For example, the control device 7 has memories such as ROM and RAM and a CPU, and programs stored in the ROM are executed by the CPU, and the control device 7 is electrically connected to the pressure sensors 71 provided on the pair pilot lines 42, respectively, and to the pressure sensors 72 provided on the pair pilot lines 44, respectively.
The pressure sensor 71 detects the pilot pressure output from the th operation device 4A, and the control device 7 increases the drive current to be supplied to the th electromagnetic proportional valve 51 as the pilot pressure output from the th operation device 4A increases, that is, the th electromagnetic proportional valve 51 outputs the higher secondary pressure as the pilot pressure output from the th operation device 4A increases, and thus the discharge flow rate of the main pump 21 increases as the operation amount of the operation unit 41 of the th operation device 4A increases.
Similarly, the pressure sensor 72 detects the pilot pressure output from the second operation device 4B. Then, the control device 7 increases the drive current to be supplied to the second electromagnetic proportional valve 52 as the pilot pressure output from the second operation device 4B increases. That is, the second electromagnetic proportional valve 52 outputs a higher secondary pressure as the pilot pressure output from the second operation device 4B is higher. Accordingly, the discharge flow rate of the second main pump 23 increases as the operation amount of the operation portion 43 of the second operation device 4B increases.
The control device 7 determines whether or not the th electromagnetic proportional valve 51 functions normally based on monitoring of the drive current supplied to the th electromagnetic proportional valve 51 (the drive current flowing is measured at that time, the same applies hereinafter), and the control device 7 determines whether or not the second electromagnetic proportional valve 52 functions normally based on monitoring of the drive current supplied to the second electromagnetic proportional valve 52.
More specifically, the control device 7 can determine whether or not the solenoid, which is a component of the electromagnetic proportional valve (51 or 52), is disconnected or whether or not a contact failure has occurred in the connector of the harness connected to the solenoid by comparing the command current output from the control device 7 with the actually measured drive current, and when it is determined that both the th electromagnetic proportional valve 51 and the second electromagnetic proportional valve 52 are functioning normally, the control device 7 sets the drive current to be supplied to the third electromagnetic proportional valve 53 to zero.
On the other hand, in , when it is determined that the th electromagnetic proportional valve 51 is not functioning properly, the control device 7 changes the drive current to be supplied to the third electromagnetic proportional valve 53 in accordance with the pilot pressure output from the th operation device 4A, that is, the control device 7 controls the third electromagnetic proportional valve 53 so that the third electromagnetic proportional valve 53 outputs a higher secondary pressure as the pilot pressure output from the th operation device 4A is higher, whereby the discharge flow rate of the th main pump 21 increases as the operation amount of the operation unit 41 of the th operation device 4A increases.
When it is determined that the second electromagnetic proportional valve 52 does not function normally, the control device 7 changes the drive current to be supplied to the third electromagnetic proportional valve 53 in accordance with the pilot pressure output from the second operation device 4B. That is, the control device 7 controls the third electromagnetic proportional valve 53 such that the higher the secondary pressure is output from the third electromagnetic proportional valve 53 as the pilot pressure output from the second operation device 4B is higher. Accordingly, the discharge flow rate of the second main pump 23 increases as the operation amount of the operation portion 43 of the second operation device 4B increases.
As described above, in the hydraulic system 1A according to the present embodiment, when the th electromagnetic proportional valve 51 is normal, the secondary pressure of the 0 th electromagnetic proportional valve 51 is introduced into the th regulator 22, and the tilt angle (discharge flow rate) of the th main pump 21 can be controlled by the th electromagnetic proportional valve 51, while , when the th electromagnetic proportional valve 51 does not function normally and the secondary pressure thereof becomes zero, the secondary pressure of the third electromagnetic proportional valve 53 corresponding to the operation signal output from the th operating device 4A is introduced into the th regulator 22, and the tilt angle of the th main pump 21 increases as the operation signal increases, and as a result, the th hydraulic actuator 26 can be operated at a sufficient speed.
Similarly, when the second electromagnetic proportional valve 52 is normal, the secondary pressure of the second electromagnetic proportional valve 52 is introduced into the second regulator 24, and the tilt angle (discharge flow rate) of the second main pump 23 can be controlled by the second electromagnetic proportional valve 52. in addition, , when the secondary pressure of the second electromagnetic proportional valve 52 does not function normally and becomes zero, the secondary pressure of the third electromagnetic proportional valve 53 according to the operation signal output from the second operation device 4B is introduced into the second regulator 24, and the tilt angle of the second main pump 23 increases as the operation signal increases, and as a result, the second hydraulic actuator 27 can be operated at a sufficient speed.
The third electromagnetic proportional valve 53 is a backup for both the th electromagnetic proportional valve 51 and the second electromagnetic proportional valve 52, and thus can cope with a failure or the like of the th electromagnetic proportional valve 51 and the second electromagnetic proportional valve 52 with an inexpensive configuration.
(second embodiment)
Fig. 2 shows a hydraulic system 1b according to a second embodiment of the present invention, and in this embodiment, the same components as those in embodiment are denoted by the same reference numerals, and redundant description thereof is omitted.
In the present embodiment, the th regulator 22 is connected to the secondary pressure port of the th electromagnetic proportional valve 55 through the th secondary pressure line 81, the second regulator 24 is connected to the secondary pressure port of the second electromagnetic proportional valve 56 through the second secondary pressure line 85, and the th and th secondary pressure ports of the th and second electromagnetic proportional valves 55 and 56 are connected to the sub-pump 25 through the th and 17 secondary pressure lines, respectively.
The th secondary pressure line 81 is provided with a switching valve 91. the switching valve 91 is provided to divide the th secondary pressure line 81 into a th upstream flow path 83 on the th electromagnetic proportional valve 55 side and a th downstream flow path 82 on the th regulator 22 side.
Similarly, a second switching valve 92 is provided in the second secondary pressure line 85. The second switching valve 92 is provided to divide the second secondary pressure line 85 into the second upstream flow path 87 on the second electromagnetic proportional valve 56 side and the second downstream flow path 86 on the second regulator 24 side.
The switching valve 91 is connected to the second upstream line 87 through the relay line 84, and the second switching valve 92 is connected to the upstream line 83 through the second relay line 88.
The switching valve 91 is of a pilot type that operates in accordance with the secondary pressure of the electromagnetic proportional valve 55 the switching valve 91 blocks the upstream flow path 83 and communicates the relay flow path 84 with the downstream flow path 82 in a neutral position (right position in fig. 2).
The switching valve 91 is switched to an operating position (left position in fig. 2) by the secondary pressure of the electromagnetic proportional valve 55 when the secondary pressure exceeds the set value α. in the operating position, the switching valve 91 connects the upstream flow path 83 with the downstream flow path 82 and blocks the relay flow path 84.
The second switching valve 92 is of a pilot type that operates in accordance with the secondary pressure of the second electromagnetic proportional valve 56. The second switching valve 92 blocks the second upstream flow passage 87 and communicates the second relay flow passage 88 with the second downstream flow passage 86 in the neutral position (left position in fig. 2).
The second switching valve 92 is switched to an operating position (right position in fig. 2) by the secondary pressure of the second electromagnetic proportional valve 56 when the secondary pressure exceeds the second set value β, in the operating position, the second switching valve 92 communicates the second upstream flow path 87 with the second downstream flow path 86 and blocks the second relay flow path 88, and the second set value β may be equal to or different from the set value α.
The th and second electromagnetic proportional valves 55, 56 are of a proportional type that outputs a higher secondary pressure as the drive current increases, respectively, the th and second electromagnetic proportional valves 55, 56 are controlled by the control device 7, that is, the control device 7 supplies the drive current to the th and second electromagnetic proportional valves 55, 56, however, only a signal line is drawn in fig. 2 to simplify the drawing.
The control device 7 increases the drive current to be supplied to the th electromagnetic proportional valve 55 as the pilot pressure (operation signal, the same applies hereinafter) output from the th operation device 4A increases, and more specifically, the control device 7 supplies the drive current to the th electromagnetic proportional valve 55 so that the 1 th electromagnetic proportional valve 55 outputs the second pressure between the minimum value and the maximum value larger than the 2 th set value α in accordance with the operation signal output from the 0 th operation device 4A, whereby the th switching valve 91 is maintained at the operating position, and thus, the th electromagnetic proportional valve 55 outputs the higher second pressure as the pilot pressure output from the th operation device 4A increases to the regulator 22 as the control pressure increases, whereby the discharge flow rate of the main pump 21 increases as the operation amount to the operation unit 41 of the th operation device 4A increases.
Similarly, the control device 7 increases the drive current to be supplied to the second electromagnetic proportional valve 56 as the pilot pressure output from the second operation device 4B increases, and more specifically, the control device 7 supplies the drive current to the second electromagnetic proportional valve 56 in such a manner that the second electromagnetic proportional valve 56 outputs a secondary pressure between the minimum value and the maximum value that is greater than the second set value β in accordance with the operation signal output from the second operation device 4B, whereby the second switching valve 92 is maintained at the operating position, and the second electromagnetic proportional valve 56 outputs a higher secondary pressure to the second regulator 24 as the pilot pressure output from the second operation device 4B increases, whereby the discharge flow rate of the second main pump 23 increases as the operation amount to the operation portion 43 of the second operation device 4B increases.
The control device 7 determines whether or not the th electromagnetic proportional valve 55 functions normally based on the monitoring of the drive current supplied to the th electromagnetic proportional valve 55, and the control device 7 determines whether or not the second electromagnetic proportional valve 56 functions normally based on the monitoring of the drive current supplied to the second electromagnetic proportional valve 56.
When it is determined that the th electromagnetic proportional valve 55 is not functioning normally, the control device 7 controls the second electromagnetic proportional valve 56 so as to output a higher secondary pressure as the pilot pressure output from the th operating device 4A is higher, whereas when it is determined that the second electromagnetic proportional valve 56 is not functioning normally, the control device 7 controls the th electromagnetic proportional valve 55 so as to output a higher secondary pressure as the pilot pressure output from the second operating device 4B is higher, the th electromagnetic proportional valve 55 is not functioning normally.
As described above, in the hydraulic system 1B according to the present embodiment, when the st electromagnetic proportional valve 55 is normal, the th switching valve 91 is located at the operating position, and the secondary pressure of the st electromagnetic proportional valve 55 is introduced into the th regulator 22, so that the tilting angle (discharge flow rate) of the th main pump 21 can be controlled by the th electromagnetic proportional valve 55, whereas, when the th electromagnetic proportional valve 55 does not function normally and the secondary pressure thereof becomes zero, the th switching valve 91 is switched to the neutral position, and the secondary pressure of the second electromagnetic proportional valve 56 corresponding to the operation signal output from the th operating device 4A is introduced into the th regulator 22, and thus the tilting angle of the th main pump 21 increases as the operation signal increases, and as a result, the th hydraulic actuator 26 can be operated at a sufficient speed.
Further, although the discharge flow rate of the second main pump 23 is also increased because the secondary pressure of the second electromagnetic proportional valve 56 is also directed to the second regulator 24, the hydraulic oil discharged from the second main pump 23 is returned to the accumulator through an unloading line or a central bypass line, which is not shown, as long as the second operating device 4B is not operated, and there is no particular problem, when the electromagnetic proportional valve 55 does not function normally and the secondary pressure thereof becomes zero and both the third operating device 4A and the second operating device 4B are operated, the operation signal of the larger side is selected, whereby the tilt angle (discharge flow rate) of the third main pump 21 and the second main pump 23 can be controlled by the second electromagnetic proportional valve 56.
Similarly, when the second electromagnetic proportional valve 56 is normal, the second switching valve 92 is in the operating position, and the secondary pressure of the second electromagnetic proportional valve 56 is introduced into the second regulator 24, so that the tilt angle (discharge flow rate) of the second main pump 23 can be controlled by the second electromagnetic proportional valve 56, in addition , when the second electromagnetic proportional valve 56 does not function normally and the secondary pressure thereof becomes zero, the second switching valve 92 is switched to the neutral position, and the secondary pressure of the electromagnetic proportional valve 55 corresponding to the operation signal output from the second operation device 4B is introduced into the second regulator 24, so that the tilt angle of the second main pump 23 increases as the operation signal increases, and as a result, the second hydraulic actuator 27 can be operated at a sufficient speed.
Further, although the discharge flow rate of the third main pump 21 is also increased because the secondary pressure of the electromagnetic proportional valve 55 is also directed to the regulator 22, the discharge flow rate of the working oil discharged from the third main pump 21 is returned to the tank through an unloading line or a center bypass line not shown in the figure as long as the operation device 4A is not operated, and there is no particular problem, when the second electromagnetic proportional valve 56 does not function normally and the secondary pressure thereof becomes zero and both the operation device 4A and the second operation device 4B are operated, the operation signal of the larger side is selected, whereby the tilt angle (discharge flow rate) of the third main pump and the second main pump 23 can be controlled by the second electromagnetic proportional valve 56.
Further, since only the switching valves 91 and 92 provided in the th secondary pressure pipe line 81 and the second secondary pressure pipe line 85 are additionally required as compared with the conventional art, it is possible to cope with a failure of the th electromagnetic proportional valve 55 and the second electromagnetic proportional valve 56, etc. with an inexpensive configuration, that is, in the present embodiment, when the side of the th electromagnetic proportional valve 55 and the second electromagnetic proportional valve 56 does not function normally, the other side can be used as a substitute therefor.
(other embodiment)
The present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the scope of the present invention.
Description of the symbols:
1A, 1B oil pressure system;
21 st main pump;
22 th th regulator;
23 a second main pump;
24 a second regulator;
3A th control valve;
3B a second control valve;
4A operating device ;
4B a second operating device;
41. 43 an operation part;
51, electromagnetic proportional valve;
52 a second electromagnetic proportional valve;
53 third electromagnetic proportional valve;
55, electromagnetic proportional valve;
56 a second electromagnetic proportional valve;
61, high pressure selection valve;
65 a second high pressure selector valve;
7 a control device;
th secondary pressure line;
82 a downstream flow path;
83 an upstream flow path;
84, th relay flow path;
85 second secondary pressure pipeline;
86 downstream flow path;
87 an upstream flow path;
88 a second relay flow path;
91 switching valve ;
92 second switching valve.
Claims (3)
- An type hydraulic system, comprising:-th and second operation devices that output operation signals corresponding to the amount of operation on the operation unit;a th pump of a variable displacement type for supplying the working oil to the th hydraulic actuator via an th control valve;a regulator that increases a tilting angle of the th pump as a control pressure increases;a variable displacement type second pump that supplies the working oil to the second hydraulic actuator via the second control valve;a second regulator that increases a tilting angle of the second pump as the control pressure increases;a electromagnetic proportional valve that outputs a higher secondary pressure as the operation signal output from the th operation device is larger;a second electromagnetic proportional valve that outputs a higher secondary pressure as the operation signal output from the second operation device is larger;a third electromagnetic proportional valve that outputs a higher secondary pressure as an operation signal output from the th operation device is larger when the th electromagnetic proportional valve is not functioning normally, and outputs a higher secondary pressure as an operation signal output from the second operation device is larger when the second electromagnetic proportional valve is not functioning normally;a th high pressure selector valve, said th high pressure selector valve selecting a th side of the secondary pressure output from said th electromagnetic proportional valve and the secondary pressure output from said third electromagnetic proportional valve as said control pressure and leading to said th regulator, anda second high pressure selector valve that selects a higher side of the secondary pressure output from the second electromagnetic proportional valve and the secondary pressure output from the third electromagnetic proportional valve as the control pressure and that leads to the second regulator.
- 2. The oil hydraulic system of claim 1,a control device for supplying a drive current to the th electromagnetic proportional valve, the second electromagnetic proportional valve, and the third electromagnetic proportional valve;the control device changes the drive current to be supplied to the third electromagnetic proportional valve in accordance with the operation signal output from the operation device when it is determined that the electromagnetic proportional valve does not function normally based on monitoring of the drive current to be supplied to the th electromagnetic proportional valve, changes the drive current to be supplied to the third electromagnetic proportional valve in accordance with the operation signal output from the second operation device when it is determined that the second electromagnetic proportional valve does not function normally based on monitoring of the drive current to be supplied to the second electromagnetic proportional valve, and sets the drive current to be supplied to the third electromagnetic proportional valve to zero when it is determined that both the electromagnetic proportional valve and the second electromagnetic proportional valve function normally.
- 3, oil pressure system, characterized in that,th operating device and second operating device outputting operation signal corresponding to operation amount of the operating part;a th pump of a variable displacement type for supplying the working oil to the th hydraulic actuator via an th control valve;a regulator that increases a tilting angle of the th pump as a control pressure increases;a variable displacement type second pump that supplies the working oil to the second hydraulic actuator via the second control valve;a second regulator that increases a tilting angle of the second pump as the control pressure increases;a -th electromagnetic proportional valve connected to the -th regulator via an -th secondary pressure line, for pressurizing a higher secondary pressure as the control pressure to the -th regulator output as the operation signal output from the -th operation device is larger;a second electromagnetic proportional valve connected to the second regulator via a second secondary pressure line, the higher secondary pressure being output as the control pressure to the second regulator as the operation signal output from the second operation device is larger;a th switching valve provided in a form of cutting off the th secondary pressure line into a th upstream flow path on the th electromagnetic proportional valve side and a th downstream flow path on the th regulator side;a second switching valve provided in a form of cutting off the second secondary pressure line into a second upstream flow path on the second electromagnetic proportional valve side and a second downstream flow path on the second regulator side; anda control device for supplying a drive current to the st electromagnetic proportional valve in such a manner that the st electromagnetic proportional valve outputs a secondary pressure between a minimum value and a maximum value larger than a th set value in accordance with an operation signal output from the th operation device, and supplying a drive current to the second electromagnetic proportional valve in such a manner that the second electromagnetic proportional valve outputs a secondary pressure between a minimum value and a maximum value larger than a second set value in accordance with an operation signal output from the second operation device;the switching valve is connected to the second upstream path through a relay path, blocks the upstream path and communicates the relay path with the downstream path in the case of a neutral position, and switches to an operating position for communicating the upstream path with the downstream path and blocking the relay path by using a secondary pressure of the electromagnetic proportional valve when the secondary pressure exceeds the setting value;a second switching valve connected to the th upstream path through a second relay path, and configured to block the second upstream path and communicate the second relay path with the second downstream path in a neutral position, and configured to switch to an operating position in which the second upstream path and the second downstream path are communicated with each other and the second relay path is blocked by a secondary pressure of the second electromagnetic proportional valve when the secondary pressure exceeds the second set value;the control device controls the second electromagnetic proportional valve in such a manner that the second electromagnetic proportional valve outputs a higher secondary pressure as the operation signal output from the th operation device is larger when it is determined that the st electromagnetic proportional valve does not function normally according to the monitoring of the drive current supplied to the th electromagnetic proportional valve;and when it is determined that the second electromagnetic proportional valve does not function normally based on the monitoring of the drive current supplied to the second electromagnetic proportional valve, controlling the th electromagnetic proportional valve in such a manner that the th electromagnetic proportional valve outputs a higher secondary pressure as the operation signal output from the second operation device is larger.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2017067527A JP2018168977A (en) | 2017-03-30 | 2017-03-30 | Hydraulic system |
| PCT/IB2018/053503 WO2018178961A1 (en) | 2017-03-30 | 2018-05-18 | Hydraulic system |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN110741169A true CN110741169A (en) | 2020-01-31 |
Family
ID=63677226
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201880019230.9A Pending CN110741169A (en) | 2017-03-30 | 2018-05-18 | Oil pressure system |
Country Status (3)
| Country | Link |
|---|---|
| JP (1) | JP2018168977A (en) |
| CN (1) | CN110741169A (en) |
| WO (1) | WO2018178961A1 (en) |
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Also Published As
| Publication number | Publication date |
|---|---|
| WO2018178961A1 (en) | 2018-10-04 |
| JP2018168977A (en) | 2018-11-01 |
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